The Right Sound Level

Most audible alarm devices are available in a large range of sound levels. As mentioned earlier, the challenge is to determine which of these best suits your product application.

The loudness of sound heard depends upon, among other things, the hearing sensitivity of the
listener, the frequency of the sound, the distance to the listener, the density and humidity of the air, the design of the sound signal, and the voltage applied.

One of the most popular Mallory Sonalert sounds is the continuous tone operating at 2900 Hz. Other audible sounds are created by varying the oscillating signal. Fast pulses, slow pulses, short pulses, warbles, chimes, and chirps are readily available options to the Mallory Sonalert. The magnitude of the sound in this piezo-ceramic device is controlled by the drive circuit and the amount of power it applies to the piezo crystal, the size of the crystal, and the size of the sound chamber.

Something important to keep in mind when comparing the dB output of different sound devices is that the distance from the device where the measurement was taken must be consistent. For distances shorter than 50 meters, sound pressure drops approximately 6 dB each time the distance traveled is doubled. Variations as much as ± 8 dB may occur inside a room or around large objects, such as buildings, due to echo cancellation and reinforcement effects.
Mallory Sonalert standard measurements documented in technical literature are made at a distance of two feet in an anechoic chamber.